Mechanical stoker



Jan. M, 1936. J. A. HOFFMAN MECHANICAL STOKER 4 Shefs-Sheet 1 Filed May 29, 1954 ammo mu :krome A H ffman,

3am M, 193 J. A. HOFFMAN 2,027,591

MECHANICAL STOKER Filed May 29, 1934 4 Sheets-Sheet 2 6 stoker and the Patented Jan. 14, 1936 MECHANICAL STOKER Jerome A.

acteristcs, a feeding and Hoffman Detroit, Mich,

Hoffman, Detroit, Micln, assignor to Combustion Engineering Company,

a corporation of Michigan 1 Application May 29, 1934, Serial No. 12am 4 Claims. (01-. l e-10o) This invention relates mechanical stokers. Mechanical stokers embody among other charagitating means generally interposed between the hopper of the such a manner as to quantities to the fuel fuel distributing mechanism, in feed hard fuel in uniform distributing mechanism.

The feeding and agitating means generally includes a chamber within stoker and has communication the main casing of the with the hopper and the casing of the distributing mechanism.

A reciprocating member is mounted in the feedchamber ing and agitating tion and feed of the fuel to effect the agitaand, the discharge of the same to the distributing mechanism for action on the fuel to effect its uniform delivery to the furnace. Mechanical stokers of this character are well known.

As the result of sliding or reciprocating movement of the feeding and agitating element of the feeding and agitating means there is considerable wear on the floor or bottom and sides of the feeding means chamber,

incident to friction, due to reciprocating or sliding engagement of the feeding and floor the life of the stoker,

element with the sides the chamber, impairing reducing eficiency, and

and agitating or bottom of necessitating replacementsat the cost of inconvenience, time, labor, and money, and sometimes, necessitating installment of an entirely new for wear occasioned incident stoker. The chance to friction in the feeding and agitating chamber and parts thereof is great.

Therefore,

the main object of the present invention is to provide a removable metallic or other lining member for installation in the feeding and agitating device chamber to take the wear incident to operation and protect the stationary stoker structure which may be readily moved from the feeding against undue wear placed in and quickly remeans chamber, permitting ready replacements, repair or for other reasons permitting removal of the lining member and thereby effectively the stoker and rendering placements, due to wear, erably less than stallment of a new prolonging the life of it possible to make reat an expense considthe expense required for the infeeding means or a completely new stoker, avoiding waste of time for repairs or replacements and providing for eiilcient operation at comparatively little cost in upkeep of the stoker.

With these and other objects in view,

the inhereto appended, it being ous changes in the form, details of construction, w

understood that variproportion, and minor ithinthe scope of the Fig. 1 is a side elevation of a stoker in which the present invention is employed.

Fig. 2 is a front view of one type of stoker.

Fig. 3 is a vertical sectional view on the line 3--3ofFi8.2.

Fig. 4 is a horizontal sectional view on the line to 4-4 of Fig. l. 1

Fig. 5 is a front elevation of the upper portion of the main casing or housing of the stoker Fig. 6 is a plan view of the upper portion of the main casing or housing of the stoker.

Fig. 7 is a longitudinal vertical sectional view of the upper portion of the main casing or housing of the stoker.

Fig. 8 is an elevation of the lining member employed in the upper portion of the main casmg or housing of the stoker.

Fig. 9 is a plan view of the lining member.

Fig. 10 is a longitudinal vertical sectional view of the lining member.

Referring now more particularly to the accompanying drawings, the reference character X indicates, generally, a stoker including a casing embodying upper and lower casing sections B and C and a rear section D. A hopper I is secured to the top of the upper section B in any suitable manner, as for instance, by means of angle bars 2 and suitable fastenings 2'.

The upper section B is illustrated particularly in Figs. 5, 6 and '7, wherein it will be seen that said upper casing section includes side walls 3, having depending side portions t, a front connecting cross wall 5 and a rear connecting cross wall 6 from which latter depends a rearwardly at its lower portion and from the edge of the walls 3 to the edge of the depending portions t constituting a part of the enclosure of the fuel distributing chamber E hereinafter described. The depending side portions 4 of the sides 3 of the casing B are also connected by a cross member including an upper horizontal flange Ill, 9. lower horizontal flange II and a vertical web forming a curved wall 12 having bearings 9. Of these, the flange I0 is, in the usual construction, extended forwardly a substantial distance to form of itself a supporting surface for the reciprocating feed means, but in the present construction it is simply a narrow flange for a purpose which will presently appear.

The upper horizontal flange ID at one end 5 has a forwardly longitudinally extending narrow portion l3 along the inner side of the wall 3 and at the other end the horizontal flange Ill has a forward longitudinally extending narrow flange l4. These flanges Ill, l3 and Il provide 0 a suitable supporting means for the lining'memher-hereinafter more fully described.

The space within the side walls 3 and the end walls 5- and 6 and the upper part of the curved wall 8, above said flanges l0, l3 and H,

. constitutes a. feeding chamber a for the reciprocating fuel feeding and agitating means indicated, generally, by the letter F and said flanges 10, I3 and I provide a front opening a adjacent the rear discharge opening a" in the bottom of the chamber a, providing for lightness in structure of the section B in which said chamber is formed. The rear opening is that opening which is arranged adjacent the furnace (not shown) as may be gathered by reference to Fig. 2 wherein is illustrated a front view of the stoker. The feeding and agitating means F, by reason of its reciprocation in the chamber a, causes considerable wear, incident to friction, due to the reciprocating of the feeding and agitating means.

As to how the feeding means is reciprocated' is more or less immaterial as regards my invention as involved in this application, as will be readily apparent from what appears hereinafter. Sumce it to state that the feeding and agitating means F includes a slidable element l5 and a stepped member l6 connected thereto, there being one or more openings I! in the feeding means between the slide l6 and the stepped member l6, as shown particularly in Fig. 3, for the passage of fuel received from the hopper as the feeding and agitating means reciprocates in the chamber a. The underside of the slide l5 has a recess l1 therein to receive one end of an arm l8 mounted at its side portions on a shaft l9, journaled in bearings I8. Although forming no part of the present invention, it may be said that arm 18 is shifted forwardly and rearwardly to actuate the slide II by an eccentric bracket, not shown, which is located externally of the casing, and the structure, function and operation of which'are well known in the art. A gear wheel 20 on a rotatable shaft 25 is driven by a pinion 2| on the distributing mechanism drive shaft 22, journaled in water cooled bearings 23.

The shaft 22 is driven in any suitable manner as for instance by a sprocket wheel 24 connected by a chain (not shown) or otherwise, there being suitable operative connections indicated, generally, by the letter G, between the shaft l9 and the'shaft 25, as illustrated in Figs. 1, 3 and 4. A detailed description of the mountings of the shafts and the specific type of operating means for driving and operating the shafts in synchronism or timed relation seems unnecessary as same do not enter into the present invention furtherthan may be necessary to illustrate a mechanical stoker with which my present invention is concerned. My invention is concerned particularly with respect to a removable and readily replaceable lining member in the feeding means chamber a of the stoker, as previously stated to overcome defects, such as outlined above, and to provide for greater efliciency and life of the stoker, I provide a suitable lining device or member, as it may be properly termed, as indicated by the reference character H.

My improved lining device or member H is substantially U-shaped in cross section and composed preferably of metal and includes a floor portion 26, and opposite upstanding sides 21 having narrow outwardly projecting vertical ribs which is opposite to the flange In, short of the 10- forward ends of the sides 21, as shown particularly in Figs. 3 and 10, and at its rear end the floor portion 26 has a downwardly directed transversely disposed lip 3|, extending the width of said floor portion, and adapted to overhang 15 the transverse supporting flange it), throughout the length of the latter (see Fig. 3) and extends into the fuel discharge opening to shield or protect the rear edge of flange Hi from undue wear with the sides 2! of the lining member 20 H also having the ends projecting downwardly along and rearwardly beyond said lip, as shown particularly in Fig. 10 and having their upper edges notched as at 21' for a purpose presently explained.

Thus the lining member H is composed of metal and shaped or formed according to the cross sectional shape and size of the chamber a of the upper casing section B in which the feeding and agitating means reciprocates and 30 in which lining member the feeding means is mounted and on the floor 26 of which lining the slide portion ii of the feeding and agitating means operates to feed the fuel uniformly to the distributing chamber E through the throat 32 of the latter between the lip 3| and the downwardly extending casing portion 1-8 and the sides 21 of the lining member to the furnace (not shown) the stoker being secured to the front wall of the furnace in any suitable manner or as 40 and all as described more in detail in my copending application, filed May 29, 1934, Serial No. 728,186.

When the lining device or member H has been placed in operative position in the casing 45 section B, that is, in the chamber a, it may be secured therein in any ,suitable manner. One form of means for this purpose is to provide the floor portion 26 with screw threaded apertures 38 to receive screw threaded bolts 50 39 which take working fit in the screw threaded openings 40 in the supporting flanges l3 and II. The sides may have screw threaded openings H and 42 to receive screw threaded bolts 43 and 44, respectively, which operate in the 55 sides of the casing A. The upper edges of the sides 3 of the chamber a have oppositely disposed recesses 45 at the front thereof to receive a holding-down bar 46 which engages in said notches 21' of the lining member H to further on aid in securing the lining member H in operative position. The holding-down; bar 46 may be readily and tightly secured by bolts 41 (see Fig. 1). It should be readily understood, that by removing the various bolts, including the g5 bolts of the holding-down bar-46 the lining device or member H may be removed to permit of removal of the lining member from the easing A, if for any reason it be desired to remove the lining device from the casing A. 7

To mount the reciprocating and agitating means in the lining device or member H, I secure within the latter, on the side walls 21 thereof, guide blocks 41 between which and the aoa'asei feeding means is guided. I'hese blocks di have upwardly directed ends 48 (see Fig. 3.) and are secured by bolts 9 to the sides 21 of the lining member H. These bolts 49 enter threaded openings 5% (see Fig. 10) in the side walls of the metallic lining member H by virtue of which, the blocks are fixed but detachably removably mounted in the lining member H. By virtue of the holding-down bar 46 the feeding means may be held and guided in true horizontal reciprocating position backwardly and forwardly within the lining member H on the bottom of the latter, operating through the opening 55 at the rear of and between the sides by any suitable operating means, as previously stated, which operating means need not be described in detail herein.

A casing or enclosure 34 may be secured in any suitable manner to the side of the casing to enclose the operating parts between said shafts, as will be seen by reference to Fig. 2.

In conclusion it will be noted that the lower portion of the upper casing section B may be welded or otherwise securedto the lower casing section C and that the section D may be welded or otherwise secured to the stoker casing. The entire casing may be formed in one piece rather than in sections as described, especially upper and lower chamber sections B and C.

What is claimed is:

1. A mechanical stoker having a feed chamber, side and end walls for said chamber, a transverse wall intermediate the ends of the chamber and spaced from the rear end wall to form therewith 'a feed throat through which the chamber discharges, said transverse wall and the lower forward portions of the side walls having flanges in the same horizontal plane with one another and cooperating to form a skeleton base for the chamber, reciprocating feed means in said chamber, means for delivering to a furnace the fuel discharged by said reciprocating feed means through the feed throat and a liner for said feed chamber having a bottom plate seated on the said cooperating flanges of the side walls and transverse wall and forming a supporting surface thereacross for the reciprocating feed means, said liner bottom plate having a rear downturned lip at the rear of, and effectively protecting, the upper rear edge of the said transverse wall, and said liner having side walls along the side walls of the feed chamber and extending substantially rearwardly of the bottom plate along the sides of the said feed throat.

2. A mechanical stoker having a feed chamber, side and end walls for said chamber, a transverse wall intermediate the ends of the chamber and spaced from the rear end wall to form therewith a feed throat through which the chamber discharges, said transverse wall and the lower forward portions of the side walls having flanges in the same horizontal plane with one another and cooperating to form a skeleton base for the chamber, reciprocating feed means in said chamber, means for delivering to a furnace the fuel discharged by said reciprocating feed means through the feed throat, and a liner for said feed chamber having a bottom plate seated on the said cooperating flanges of the side walls and transverse wall and forming a supporting surface thereacross for the reciprocating feed means, said liner bottom plate having a rear downturned lip at the rear of, and effectively protecting, the upper rear edge of the said transverse wall, and said liner having side walls along the side walls of the feed chamber and extending substantially rearwardly of the bottom plate along the sides of the said feed throat, the 5 upper rear edges of the said side walls of the liner member having notches therein, and a hold-down member in connection with the side walls of the feed chamber and extending into said notches for holding the liner member firmly m in place.

3. In a mechanical stoker, a casing including a fuel feeding chamber, a reciprocating fuel feeding device operating in said chamber, the chamber having side walls and end walls and an 15 intermediate transverse wall provided with an. upper transverse flange, said side walls having laterally spaced longitudinal flanges in horizontal alinernent with the transverse flange, said longitudinal and transverse flanges providing a my front opening in the bottom of the chamber and being spaced from the rear end wall providing a rear discharge opening, means for delivering to a furnace the fuel discharged by the reciprocating feed device through said rear discharge 25 opening, and a lining member including side walls and a floor portion, the side walls of the lining member extending along the side walls of said chamber and the floor portion being supported on said longitudinal and transverse flanges and constituting a support for said reciprocating feed device over a portion of said front opening, said floor portion of said lining member having at its rear end a downwardly directed transverse lip overhanging said transverse flange and extending into said fuel discharge opening to protect the upper rear edge of said transverse wall, and means in connection with the upper portions of the chamber side walls and engaging the side walls of the 49 lining member for removably seeming said lining member in position.

4. In a mechanical stoker, a casing including a fuel feeding chamber having side walls and end walls of which the side walls have laterally 5 spaced and opposing longitudinal flanges, an intermediate transverse wall across said chamber having an upper flange in the same horizontal plane with said side wall flanges and spaced from the rear end wall to form therewith a rear fuel 50 discharge opening, reciprocating fuel feeding means in said chamber, means for delivering to a furnace the fuel discharged by the reciprocating feed means through said discharge opening, and a lining member including side walls and a 55 floor portion, the side walls of the lining member extending'along the side walls of the chamber and the floor portion thereof being supported at its side and rear edges on said flanges and having at its rear edge a downwardly directed on transverse lip overhanging the transverse flange and extending into said fuel discharge opening to protect the upper rear edge of the transverse wall, means for detachably connecting the floor portion to the side wall flanges, means for de- 5 tachably connecting the side walls of the lining member to the side walls of the chamber, and a hold-down bar removably mounted on the chamber side walls'and engaging the upper edges of the side walls of the lining member to assist in 7 holding the lining member in position.

JEROME A. HOFFMAN. 

